[PATCH v2 2/2] gpio: search for gpio label if gpio is not found through bank name

[Heiko Schocher]

dm_gpio_lookup_name() searches for a gpio through
the bank name. But we have also gpio labels, and it
makes sense to search for a gpio also in the labels
we have defined, if no gpio is found through the
bank name definition.

This is useful for example if you have a wp pin on
different gpios on different board versions.

If dm_gpio_lookup_name() searches also for the gpio labels,
you can give the gpio an unique label name and search
for this label, and do not need to differ between
board revisions.

Signed-off-by: Heiko Schocher <hs at denx.de>
---

Example on the aristainetos board:

=> gpio clear wp_spi_nor.gpio-hog
gpio: pin wp_spi_nor.gpio-hog (gpio 47) value is 0
=>

before this patch, you need to know where your
pin is:

=> gpio clear GPIO2_15
gpio: pin GPIO2_15 (gpio 47) value is 0
=>

travis build:

Changes in v2:
- add comment from Simon Glass
  move code into seperate function dm_gpio_lookup_label()
  add test if dm_gpio_lookup_label() works

 drivers/gpio/gpio-uclass.c | 38 ++++++++++++++++++++++++++++++++++++++
 test/dm/gpio.c             |  7 +++++++
 2 files changed, 45 insertions(+)

diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index 90fbed455b..fb87ef9810 100644
--- a/drivers/gpio/gpio-uclass.c
+++ b/drivers/gpio/gpio-uclass.c
@@ -52,6 +52,37 @@ static int gpio_to_device(unsigned int gpio, struct gpio_desc *desc)
 	return ret ? ret : -ENOENT;
 }
 
+/**
+ * dm_gpio_lookup_label() - look for name in gpio device
+ *
+ * search in uc_priv, if there is a gpio with labelname same
+ * as name.
+ *
+ * @name:	name which is searched
+ * @uc_priv:	gpio_dev_priv pointer.
+ * @offset:	gpio offset within the device
+ * @return:	0 if found, -ENOENT if not.
+ */
+static int
+dm_gpio_lookup_label(const char *name, struct gpio_dev_priv *uc_priv,
+		     ulong *offset)
+{
+	int len;
+	int i;
+
+	*offset = -1;
+	len = strlen(name);
+	for (i = 0; i < uc_priv->gpio_count; i++) {
+		if (!uc_priv->name[i])
+			continue;
+		if (!strncmp(name, uc_priv->name[i], len)) {
+			*offset = i;
+			return 0;
+		}
+	}
+	return -ENOENT;
+}
+
 int dm_gpio_lookup_name(const char *name, struct gpio_desc *desc)
 {
 	struct gpio_dev_priv *uc_priv = NULL;
@@ -80,6 +111,13 @@ int dm_gpio_lookup_name(const char *name, struct gpio_desc *desc)
 			if (!strict_strtoul(name + len, 10, &offset))
 				break;
 		}
+
+		/*
+		 * if we did not found a gpio through its bank
+		 * name, we search for a valid gpio label.
+		 */
+		if (!dm_gpio_lookup_label(name, uc_priv, &offset))
+			break;
 	}
 
 	if (!dev)
diff --git a/test/dm/gpio.c b/test/dm/gpio.c
index 9003ea82c7..1f1bf680c5 100644
--- a/test/dm/gpio.c
+++ b/test/dm/gpio.c
@@ -125,6 +125,13 @@ static int dm_test_gpio(struct unit_test_state *uts)
 	ut_assertok(dm_gpio_set_value(desc, 0));
 	ut_asserteq(0, dm_gpio_get_value(desc));
 
+	/* Check if lookup for labels work */
+	ut_assertok(gpio_lookup_name("hog_input_active_low", &dev, &offset,
+				     &gpio));
+	ut_asserteq_str(dev->name, "base-gpios");
+	ut_asserteq(0, offset);
+	ut_asserteq(CONFIG_SANDBOX_GPIO_COUNT + 0, gpio);
+
 	return 0;
 }
 DM_TEST(dm_test_gpio, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
-- 
2.24.1